Flow condition tester



Feb. 26, 1946. T. B. CRAWFORD ETAL 2,395,536

' FLOW coNDlTIoN TESTER l Filed Dec. 2, 1945 Patented Feb. 2s, 1946Thomas B. Crawford Joseph E. Vilbig,

Crown Point, Ind., and Chicago, Ill., assignors to Babson Bros. Co., acorporation of Illinois Application December 2, 1943, Serial No. 512,550

2 Claims.

This invention relates to a flow condition tester; and more particularlyto portable apparatus for testing the condition of vacuum systems of thetype used in dairy barns for actuating milking machines.

One feature of this invention is that it provides an indication of theeffectiveness of the vacuum system; another feature is that it providesan indication of flow conditions in the system, and more particularlyobstructions or leaks; still another feature of this invention is .thatit enables quick `and convenient location of difficulties in the system;yet another feature is that the apparatus includes a sensitive pressureindicating device, and means for adjusting the apparatus to provideindications Within the range of the sensitive indicating means despitewide variations in the capacity of the system; a further feature of theinvention is the association of a U-tube having a light liquid thereinwith an adjustable opening and an adjustable scale; and yet a furtherfeature is the provision of means for preventing loss of liquid from theU-tube during carrying of the apparatus. Other features and advantagesof the invention will be apparent from the following specification andthe drawing, in which:

Figure 1 is a View indicating the apparatus in action on a simple vacuumsystemof the kind used in diary barns; Figure 2 is an enlarged View ofthe operative portion of the apparatus form- 'ing the subject matter ofthis invention; Figure 3 is a partial sectional view of the uppermostportion of the apparatus as shown in Figure 2. and in the same plane asthat figure; and Figure 4 is a transverse sectional view along the line4-4 of Figure 2.

' While the testing apparatus and method which is the subject matter ofthis invention is ap- I plicable to a large number of situations whereit is desirable to test flow conditions, it was particularly designedand adapted for use in testing vacuum systems of the kind generallyinstalled in a dairy barn for actuating the milking machines, and itwill be described in connection with such a system.

A dairy barn vacuum system comprises a source of vacuum, generally atank Yand pump.

`,and lengths of wall pipe connected to this source and running alongback vof each row of stalls. I'hese pipes are provided with connectingmeans at appropriate intervals, these generally being manually operablecocks termed stall cocks. When such a system is installed the ends ofthe pipes areV sometimes not properly reamed out after sawing, leavingburs which obstruct flow through the pipe at the joints; bits of hay andother dirt get into the pipes and sometimes build up obstructions which,while they do not completely block the pipe, greatly reduce theeffectiveness of the vacuum system during operation of the milkers;joints or stall cocks sometimes develop small leaks which reduce theeffectiveness; or, in other Ways, the operative eiectiveness of thesystem may be reduced below that available at the source.

In the particular embodiment of the invention illustrated herewith, acarrying case I0 provides a housing and mounting for a glass U-tube IIhaving therein water, alcohol or some other light liquid, preferablycolored. The tube would normally have a total height of only about afoot Vand a half so that -when one end is left open and the other endconnected to a point which is lower than atmospheric pressure, thedevice forms a sensitive pressure I indicating means, since a differenceof a few ounces in pressure would make quite a few inches difference inthe relative level of the liquid in theA two legs of the tube. Theright-hand side of the tube (speaking with respect to the position asshown in the drawing) has an open-end rubber tube I2 connected thereto,while the left-hand side is connected, through a rubber tube I3, to aconnector tube I4 opening into and through one wall of the main flowtube I5.. A cross bar i6 lies across the two rubber `tubes and isadapted to be clamped down on the tubes, by the use of the wing nut IIto close the tubes oi when desired. While the apparatus is being carriedfrom place to place, the

rubber tubes would be closed 01T in this manner to prevent loss ofliquid from the U-tube, and

when the apparatus was to be used, it would be stood up vertically, asillustrated in Figure 1. and the tubes unclamped or opened, asillustrated in' Figure 4. e Y

The flow tube I5 is of metal or anyl appropriate rigid material,preferably half an inch or more in diameter. A rubber tube I 8 isconnected to one end of the flow tube, the other end of this tube I8being provided with a coupler la adapted to be slipped onto a stallcock. The other end of the flow tube I5 is flared somewhat, as may bebest seen in Figure 3, andhas associated therewith a plug member I9movable toward and away from the end of the tube by rotation of themounting screw V2li. This arrangement provides means for adjusting theeffective opening to atmosphere at this left-hand end of the ilow tube.Associated with the* U- tube is a vertically movable scale 26, as may bebest seen in Figure 2. This member 26 may be slid up and down (as forexample, from a position shown in solid lines to a position shown indotted lines); and is provided with markings graduated in percentage andadapted to cooperate with the right-hand leg of the lU-tube.

Referring v"now more particularly to Figure 1, the vacuum system isillustrated as including a source of vacuum comprising a tank 2|associated with a motor driven vacuum pump 22; and avlength of pipe 23,representative of the pipe which would run along back of the stalls.

IThis pipe is connected to the tank 2! at one end, and

plugged at the other end; and'itis provided with spaced stall cocks atappropriate intervals, as the stall cocks 24a-24e. The tank is alsoprovided with a stall cock, here identified as 25, which may also beused as a drain cock.

When the service man wishes to test the effectiveness of the vacuumsystem in the dairy barn, he would rst connect the coupler Ia to thestall cock 25, adjust the plug I9 to a position considerably spaced fromthe cooperating end of the flow tube I5, and open the cock-with thevacuum pump running, o f course. The plug member I9 would then begradually moved in toward the end of the ow tube I 5, by use of theadjustment screw 20, until the pressure conditions in the flow tube I5,communicated through the connectingrtubes I4 and I3 to the left-hand legof the U-tube, were such that the liquid level vin the left-hand leg wasin the neighborhood of 4 above that in the right-hand leg, at leastsomewhere between three and iive inches. The scale member 26 would then-be moved up and down until itsl 100% marking corresponded exactly withthe level of the liquidV in the righthand leg. While, at leastin theory,the scale could be iiXed and all adjustment done by movement of the plugmember I9, this adjustment is so sensitive that it is preferable to havethe scale movable, so that there are in reality two steps of adjustmentperformed initially. mentl is necessary because the source of vacuum maycomprise a pump of `very lowcapacity only intended to handle a singlemilking machine; or it maycomprise a pump of considerable capacity This.adjust- 4 screwing the plug member I9 all the wayin until' .it fullycloses the cooperating end of the flow tube I5, whereupon connection ofthe coupler I8a vto the cock 24d (leaving it closed) will disclose eventhe most minute leak. If this cock proves `to have no leak, itis obviousthat there is an obstruction in the section of pipe between the cocks24d and 24C, and this section of pipe may be taken out and burrs orother diiiiculties removed. Also, if the test determinations showed 100%readings on the cocks 24a, 24h, 24d and 24e, but only a 25 or 50%reading, for example', when connected to stall cock 24e (and the cockopened)v a clear indication is given of the fact that the line or pipeis in good condition but that stall cock 24e is itself plugged. Ifdesired, each of the hoses used to connect the milking machine to thestall cocks may beconnected to a stall cock and the tester connected tothe other end of the hose.

When the stall cock is opened, the connector hose adapted to handle anumber of milking machines at once. many installations being intended tohand1e 18 milking machines. Because of the use of a relatively lightliquid (as contrasted with merclury) in the indicating device, it isquite sensitive to small changes in pressure; and the initial adjustmentenables determination of an initial reference point Within the desiredoperating range of the pressure indicating device regardless of thecapacity of the pump.

VA The service man would then connect the ap'- paratus to the stall cockmost remotefrom the source of vacuum, as to stall cock 24a asillustrated inFigure l. If the level of liquid in the right-hand legremains even with the 100% graduation on the scale (without any changein the position ofthe plug member I9 or of the scale member 26, oicourse), the system is in good condition and need be tested no further.If the level of liquid in the right-hand leg rises, however, as forexample to the graduation, it indicates that the effectiveness at thisfarthest stall cock under conditions of flow is poor. The whole pipe maythen lbe ilushed out with a lye solution; and if this doesr not obviatethe difficulty, the test is carried on to localize the trouble. To dothis the tester is successively connected to then becomes a part of thesystem and any obstructions in it (as by swelling of the rubber,accumulation of milk solids or the like) is shown up on the tester.

The vacuum systems used in dairybarns are almost always provided with .avacuum gauge (generally of the mechanical type as distinguished from theliquid type used in this tester), butl this gauge will not show upobstructions or diflculties which considerably reduce the eiectivenessof the milking machines. A Very sensitive pressure indicating device isneeded for this; and the Vtest must be made under conditions of flow,rather than as a matter of absolute pressure. As long as the pipe 23 wasopen at alleeven though it was seriously plugged, the pressure at thefarthest stall cock 24a would be the same as at the source if aconventional type of pressure gauge were used. The `test must be madewhile'there is a substantialV flow. of air through the system; so that,while a pressure device is used to providethe indication, the test isreally a testr of flow condition rather than of pressure.

While we have shown and described certain ernbodiments of our invention,it is to be understood,

is capable of many modifications.

that it Changes, therefore, in the construction andarrangement may bemade without departing from the spirit and scope of the invention asdisclosed in the appended claims.

1. Apparatus of the character described for indicating flow conditionsina piping system being tested, including: means for indicatingsmall'variations in fluid pressure, this indicating means comprising atransparent U-tube having a liquid of low speciiic gravity therein, anda'movable scale associated with the U-tube; means for providing aconnection between one end ofthe tube and the interior-of the pipingsystem at any one of several selective points; means for creating apartial vacuum in said system; a ilowtube connecting the other end ofthe iirst mentioned tube with said indicating means, said ilowtube-having an opening leading to the atmosphere; and adjustable meansadjacent said opening for adjustfor providing a connection between oneend of the tube and the interior of the piping system at any one ofseveral selective points; means for creating a partial vacuum in saidsystem; avow tube connecting the other end of the rst mentioned tubewith said indicating means, said flow tube having an opening leading tothe atmosphere; and adjustable means adjacent said opening for adjustingthe effective flow of atmospheric air through said opening, wherebyobstructions in l0 the piping system may be located.

THOMAS B. CRAWFORD. JOSEPH E. VILBIG.

